Feeding mechanism for rock-drills and the like.



G. R. BENNETT.

FEEDING MECHANISM FOR BOOK DRILLS'AND THE LIKE.

APPLICATION FILED 00T.24, 1908.

Patented July 19,1910.

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INVENTOR. G. E. 5 2/7/7277 G. R; BENNETT.

FEEDING MECHANISM FOR BOOK DBILLS AND THE LIKE. APPLIOATION IILBD 0012.24, 190av Patented July 19,1910.

INVENTOR. G. H, Benn eff" G. R. BENNETT.

FEEDING MECHANISM FOR ROCK DBILLS AND THE LIKE.

APPLICATION FILED OOT.24, 1909.

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inn STATES 1 GEORGE E. BENNETT, OF DENVER, COLORADd.

FEEDING MECHANISM FOR ROCK-DRILLS AND THE LIKE.

Specification of Letters Patent.

Patented July 19, 1910.

Original application filed May 4, 1908, Serial No. 430,773. Divided and this application filed October 24,

- 1908. Serial No. 459,402.

To all whom it may concern:

hing Mechanisms for Rock-Drills and the Like, of which the following is a specification.

This invention relates to certain new and useful improvements in feeding mechanisms for rock drills and other machines in which a tool is kept in constant contact with a surface upon which it impinges and is fed into the material with a velocity equal to that with which it penetrates the same.

The object of my invention is to provide a mechanism of the class named whereby the above named results are automatically attained in a highly effective and simple manner and which permits of ready adjustment to suit varying conditions.

I attain this object by the means illustrated in the accompanying drawings in the various views of which like parts are similarly designated, the. said means being identical to those shown and described in the application for patent Serial 430,7 7 3, filed May 4, 1908, of which the present application is a division. j

. In thedrawings, Figure 1 represents a side elevation of a hammer drill equipped with my improved feeding mechanism, Fig. 2- a similarview with the piston housing feed cylinder. and the adjacent portion of the supporting base in section, Fig. 3- a transverse section taken along the line 3-3, Fig. 2,, Fig. 4.'-'a cross section taken along the line 44, Fig. 2, Fig. 5- an end View of the apparatus looking in. the direction of the arrow a, Fig. 1, Fig. 6- anenlarged fragmentary view of the front end of the piston rod included in the feeding mechanism in association with the adjacent parts of the machine, Figs. 7- and 8- enlarged fragmentary views of the valve chest forming part of the feed cylinder, showing the valve and the therewith connected rod in their. extreme positions, Fig. 9- a .fragmentary sectional view of the valve rodshowing its position in relation to the hanger by which it is suspended from the rod of the.

feed piston, at the beginning of the forward stroke of the valve. Fig. 10, an. enlarged sectional view of the lower portion of the piston housing, and the base upon which it moves, together with the feed cylinder and the therewith cooperative parts. Fig. 11, an enlarged fragmentary transverse section through one of the lateral flanges on the housing and the adjacent parts of the base, showing the application of means to prevent retrograde movement of the housing and Fig. 12, a fragmentary-sectiontaken along the'line 1212 Fig. 11.

My improved feed mechanism has been shown in the drawings in operative association with a rock drill of the hammer type,

comprising a hammer housing '5 which is longitudinally movably mounted upon a stationary trough shaped base 7, by means of laterally extending flanges 6 which project into correspondingly shaped guide ways in the upper edges of the said base.

A hammer 8 is fitted for reciprocationwithin the cylindrical bore of the housing 5 and is adapted to impinge upon the ext-remity of a tool 9 which has a longitudinal movement in a chuck 10 at the fore end of the housing. a

The hammer or piston 8 is provided with a rod 12 which projects through a stuflin box 13 at the rear end of the housing and terminates in a truncated head 14.

The operating mechanism of the drill consists of a reciprocating rack 15 which terminatesin a pair of spring jaws 16,

which normally engage the head 14. The

jaws 16 have inwardly projecting bosses 1 7 which, when the rack is in its rearmost position, engage a roller 18 and cause the jaws to separate and disengage the head 14.. The

piston being thus liberated is impelled forwardly to impinge upon the tool by the eirpansive action 0 themotive fluid which is continuously introduced into the housing through a conduit '19 and is compressed during the rearmost movement of the piston.

The teeth of the rack are in mesh with those on the segmental extremity of a rocker arm 20 which is connected by. means of a pitman 21 with the wrist of a crank wheel 22 upon a shaft 23 which is operatlvely connected with a conveniently located motor or other source of energy.

The various parts of the above described operating mechanism are mounted upon an upright 24 which forms part of a horizontal beam 25 upon which the base is mounted.-

The mechanism by means of'which the ion housing is propelled in forward direction for the purpose of feeding the therewith connected tool into the substance penetrated thereby, is composed of a horizontal cylinder 26 which is rigidly secured in the trough-like member 7 of the stationary element of the apparatus and in which a piston 27 has a rec'iprocatory movement. The outwardly projecting extremity of the rod 28, which forms part of this piston, carries a collar 29 formed with an upwardly extending stud 30, upon which 'a vertically movable dog 31 is resiliently supported by means of a spiral spring 32.

The upper extremity of the dog 31 is formed with a series of ratchet-shaped teeth which normally engage correspondingly shaped teeth of a rack 33' which is rigidly secured along the under surface of and in longitudinal relation to the lower member 9 of the piston housing.

A lever 34, fulcrumed at one extremity upon the collar 29, and connected with the dog 31 by means of a link 35, serves as means to manually detach the piston 27 from the rack 33 when it is desired to vary the position of the drill housing in relation to the stationary support.

The interior of the feed cylinder 26 connects by means of ports 36 and 37, which are formed in itswall, with a valve chest 38 in which a valve 39 hasa reciprocatory movement, and which is connected with a.

source of motive fluid by means of a conduit 40. The spent fluid is exhausted from the chest 38 through two openings 41 and 42 at opposite sides of the inlet 40.

The valve 39 is composed of three pistons 43, 44 and 45 which are mounted, in spaced relation to each other, upon a rod 46, which, projecting through the end of the valve chest, is slidably supported in the apertured extremity of a hanger 47 which is suspended from the collar 29 on the piston rod 28.

A spring 57, which surrounds the rod 46 is secured at its extremities, to the end of the valve chest 38 and to a collar 48 which is secured upon orv forms part of the rod. A stop 49 is adjustably mounted upon the rod 46 between the collar 48 and the extremity of the hanger 47 and a second stop 58 is pivotally secured in a slot 59 of the rod,

between the latters extremity and the first named stop, to limit the forward movement of the valve 39 by engagement with a pin 60 which is secured transversely of the trough-shaped member 7 of the stationary support.

The stop 58 comprises two diverging arms 61 and 62 which, when the member is in its normal position, as is illustrated in 7 of the drawings, project obliquely above and aeripheral surface of the r 63, which is secured one of tles'within the slot engages the lower edge of the arm 61 for the purpose of maintaining the stop 58 resiliently in its normal position.

When the valve is in the position illustrated in Fig. 7, the pivoted stop 58 is in its normal position in which the pin (50 occupies a notch 52 in the outer extremity of the arm (32, the inlet pipe 40 is in communication with the port 36 and the steam or air is admitted behind the piston 27 which in consequence is driven forwardly and which, by reason of the connection between the rod 28 and the rack 33 on the drill housing, carries the latter with it, as rapidly as the drill steel penetrates the surface upon which it acts. When the piston 27 has terminated its forward stroke, an outwardly projecting lip 47 on the hanger 47 engages the upper edge of the obliquely extending arm 61 of the stop 58 which, in consequence, is depressed (as is illustrated in Fig. 9) and released from con tact with the stationary pin 60. The valve, being thus unobstructed, is by actuation of the erstwhile compressed spring 57, at once impelled into the position illustrated in Fig. 8 in which the port 36 is in communication with the exhaust opening 41 and the fluid supplied through the conduit 40, flows in between the pistons 44 and 45 and into the port 37 to be admitted at the other side of the piston 27. i

As by reason of its resilient connection with the collar 29' and the slanting form of the engaging teeth, the dog 31 is free to move rearwardly independent of the rack 33, the piston is at once returned to its original position when, by engagement of the hanger 47 with the stop 49, the valve 39 and the therewith associated stop 58 are again placed in the position shown in Fig. 7, and the above described operation isrepeated. It will thus be observed that by adjustment of the stop 49 on the rod 46, the stroke of the feed piston may be regulated to any desired length while the hammer. housing may be I before, is accomplished by manipulation of the lever 34.-

To prevent retrograde movement of the hammer housing upon the stationary support, whenthe machine is positioned to drill holes in an upward direction, I have provided one of the flanges 6 of the lower member 9 of the said housing with a rack 55, the ratchet shaped teeth of which are engaged by a spring actuated pawl 56 in theadjacent portion of the member 7 of the stationary support. v

wish it understood that while I have shown and described my invention in the best form now known to me, variations in the arrangement and construction of the various parts included in the mechanism may be availed of without departing from the spirit of my invention.

What I claim and desire to secure by Letwith the rack during its movement in one direction, a conduit to conduct motive fluid to either port, a valve controlling the communication between said conduit and said ports, and means to reverse the position of said valve at predetermined points of the stroke of the piston.

2; In combination with a movable element, a stationary cylinder, a piston and piston rod, a connection between the piston rod and the movable element, a valve tor admitting pressure fluid to the cylinder, a spring for normally holding said rod in one position, atwo-armed stop pivoted to the rod, an abutment to engage one of the arms, a member connected with the piston rod andmov able along the valve rod to engage the other arm of the said stop to free the stop from the abutment, and an adjustable stop on the rod to be struck by the said member for returning the valve rod against the action of the spring to. allow the two armed stop to connected with the valve,

engage the abutment, substantially as de scribed. s

3. The combination with a stationary support, of a movable element having a lon tudinal rack, a cylinder on said support aving'ports adjacent its ends, a piston within said cylinder, a valve housing in communication with said ports, a conduit to conduct motive fluid into said housing, a valve slidable in said housing to bring said ports separately in communication with sa1d conduit, a dog to connect the piston with the'rack during its movement in one direction, a rod a spring impellently engaging said rod, a stop on said rod,

an abutment on the support normally'engag.

ing said stop so as to restrain expansive act1on of sa1d spring,

a member associated with the-piston and adapted to release said sto from said abutment by engagement wit the former during movement of the piston in one direction, and a stop disposed upon the rodto be engaged by said member during the movement of the piston in opposite direction to return the valve to its original position. In testimony whereof I/have aflixed my signature in presence of two witnesses.

GEORGE R. BENNETT.

Witnesses:

G. J. RoLLANDn'r,

A. A. OGDEN. 

